MICROBIOLOGY

• Facultatively anaerobic, motile, non-lactose fermenting, Gram-negative rod.
  • Inhabits fresh and brackish waters, isolated as intestinal commensal from cold- and warm-blooded animals.
    • Although it is primarily a fish pathogen, it is also found in amphibians, reptiles, and birds, usually in marine waters.
  • Stains with Congo Red, iron-loving
• Edwardsiella spp.
  • E. tarda is the primary human pathogen.
    • It behaves similarly regarding biochemical, virulence, and clinical profile to Salmonella spp.
  • Other species mainly isolated from fish: E. hoshinae, E. ictaluri (catfish), E. piscidida